When you reply to message IGF520A with "switch pair, and swap," P/DAS
takes action that is based on the existing environment. Refer to Table 1 and to the actions labeled A through
D to determine how P/DAS will respond to this reply.
Table 1. System actions
for switch pair, and swap. Descriptions for the individual
actions follow this table.| PPRC path direction |
System action with equivalent
device geometry |
System action with different
device geometry |
|---|
| PPRC paths exist in both directions |
Action A |
Action B |
| PPRC paths only exist from primary
to secondary |
Action C |
Action D |
Explanation of terms: - Paths exist in both directions means that a path exists
from the primary volume’s storage control to the secondary volume’s
storage control, and another path exists from the secondary to the
primary. The PPRC pair is able to operate in either direction, and
the environment is ready to allow a switch of the PPRC pair from secondary
to primary. When paths exist only from the primary to the secondary,
the environment is not set up to allow data flow from the target volume
to the source volume.
- Equivalent device geometry means that the primary and secondary
volumes have equivalent track sizes and volume capacity.
- Different device geometry means that the primary and secondary
volumes have the same track size but the secondary has a larger volume
capacity than the primary.
|
The following specific actions relate to Table 1.
The table refers to these actions according to your existing environment.